Re-add point-in-time restore

testdata/Makefile

@@ -1,8 +1,13 @@
 .PHONY: default
 default:
 	make -C find-latest-generation/ok
+	make -C index-by-timestamp/no-wal
+	make -C index-by-timestamp/ok
+	make -C index-by-timestamp/snapshot-later-than-wal
 	make -C generation-time-bounds/ok
 	make -C generation-time-bounds/snapshots-only
 	make -C replica-client-time-bounds/ok
 	make -C snapshot-time-bounds/ok
+	make -C snapshot-index-by-timestamp/ok
 	make -C wal-time-bounds/ok
+	make -C wal-index-by-timestamp/ok